waste gate source

[EclipticalGS]

This has been sort of rattling around in me for a while, E3Big16G, hx40, doesnt really matter which turbo, i talk to people that say Running the wastegate boost source from just a boost source like the turbo or an intercooler pipe is not good, because when you shut the throttle plate (let off gas) the piping will still expell a little more pressure opening the wastegate, then running from the intake manifold when throttle palte is closed will add suction and close the wastegate immediately, then when throttle is reopened, then it rebuilds the boost.

Well i was always aware that if you ahve a 14 pound spring, that waste gate flapper/ valve will not start oepning until ~12 psi, when there is even 11psi on a 14psi spring, that wastegate is not open at all...

Well tell me if im wrong, i am arguing with my freinds over this, they seem tothink it is wrong im running off just my J-pipe....They think i need vacuum too, to close the flapper after shifting, saying it'll build boost faster because the flapper was closed while shifting.

Whats your opinion.

Could there be a reason mitsubishi ran to the intake.

 

[Dsmj89]

There's a lot of things mitsubishi did that wasn't necessary to do, such as use a plastic bov, balance shafts, etc... These are the small things that make dsm more daily driver friendly cars.

Just run the wastegate pressure off your j-pipe or compressor housing as is always recommended and you will be fine.
Why mitsubishi decided to "T" in the factory bcs between the wastegate and turbo and then run it to the intake is beyond me, maybe a DSM guru can chime in on this one and explain what was their purpose for doing so.

 

[Talon2139]

When the throttle plate goes closed there is a vacuum immediately. I think your friends are full of it, unless you do not have a blow off valve, though i think you do. The wastegate is only pushed through boost so when you let the throttle plate closed, there is no more boost and a vacuum would only shut it faster, but there is also the calculation of fuel, with the ecu. So there is no more heat going to the turbo to be spinning it faster.

 

[EclipticalGS]

what im asking.....

1. Wastegate running off intake. When you shift, throttle plate closes, forcing the wastegate to close, therefore, the wastegate is closed before the "re-opening of the throttle plate" which allows faster boost building, no escaping of exhaust out of the wastegate.

2. Wastegate running off j-pipe, When you shift, throttle plate closes, BOV opens and expells the pressure, but does not expell it to a negative vacuum (the IC piping does Not go to 0 when pressure is relieved, the wastegate will therefore not see any vacuum from the j-pipe, so when you shift, the wastegate will stay a little bit open with the pressure left in the IC piping after blowing off. Which in turn makes slower boost build.

Which sounds right????

 

[nytescion]

In example 2 you said that the pressure in the IC pipe goes to 0. So what pressure would be keeping the wastegate open?

I think that running a Vacuum/boost source to the wastegate would cause it to cycle faster but most of us don't have the provisions on the manifold to run to wastegate. All the extra line involved i think would negate any benefit you would get out of it anyway. Are any other cars that come factory turbocharged come with a boost/vaccum source to the wastegate?

 

[EclipticalGS]

what im asking.....

but does not expell it to a negative vacuum (the IC piping does Not go to 0 when pressure is relieved,

Which sounds right????

I said the IC piping pressure does Not go to 0...

 

[95blackGsTurbo]

People are always going to talk and say their way is the best. Fact is, the wastegate pull's its vacuum from the place it does for a certain reason. If it isn't broke don't fit it. Does it really matter if the wastegate is open while the thottle plate is shut? Run it off the turbo.

 

[nytescion]

I said the IC piping pressure does Not go to 0...

Sorry misread that a couple times no doubt. But still how much does it take to start to crack the a wastegate. Everyone's wastegate or spring pressures are different. Just use a compressor to find out. But i'm sure it's alot more than what the compressor is putting out after the bov closes and the car is between shifts or at idle..

 

[EclipticalGS]

gahh...Now i figured out with my TB0363 internally gated volvo turbo, i hand pumped 2 psi into the wastegate and sure enough that fricking wastegate flap started peeking open. So even 1-2 psi in the IC piping from the compressor inbetween a quick shift will still have the wastegate opened a crack. but hey i guess ill just go the easy route...compressor to wategate.. thanks!!

 

[nytescion]

just cause we said it wont matter if it sees vacuum or not shouldn't deter you from atleast trying it. who knows maybe you'll like it setup that way more

 

[EclipticalGS]

You dont think that that wastegate snapping closed after a shift may help the turbo with spoolup time.

Now that i have an open dump wastegate, ill run both, and im sure ill be able to tell if that wastegate is open or not after a shift with running from my j-pipe. See which works better.

Also, if me pumping 2psi of pressure on my turbo and the wastegate starts opening then thats already a loss of exhaust that could help spool the turbo faster.